Parse and store both col align and col width spec for later use

* lisp/org-exp.el (org-store-forced-table-alignment): Parse
the column cookie for both alignment and width specification.
Store the resulting value in `org-col-cookies' property.
Retire the previously used `org-forced-aligns' property for
consistency.  Renamed local variable `aligns' to `cookies'.
* lisp/org-html.el (org-format-org-table-html): Use
`org-col-cookies'.  Renamed local variable forced-aligns to
col-cookies.

This is a preparatory patch.  A backend can look at the colwidth
specification and (at it's discretion) use it to control relative
sizes of individual columns in a table.  At this moment, it is unclear
whether the widths used to control the display of table in Org buffer
can be overloaded to also control the formatting of table in a
backend.

Refer following discussion with Matt Price:
http://lists.gnu.org/archive/html/emacs-orgmode/2011-08/msg01053.html

lisp/org-exp.el

@@ -2002,23 +2002,28 @@ When it is nil, all comments will be removed."
 
 (defun org-store-forced-table-alignment ()
   "Find table lines which force alignment, store the results in properties."
-  (let (line cnt aligns)
+  (let (line cnt cookies)
     (goto-char (point-min))
-    (while (re-search-forward "|[ \t]*<[lrc][0-9]*>[ \t]*|" nil t)
+    (while (re-search-forward "|[ \t]*<\\([lrc]?[0-9]+\\|[lrc]\\)>[ \t]*|"
+			      nil t)
       ;; OK, this looks like a table line with an alignment cookie
       (org-if-unprotected
        (setq line (buffer-substring (point-at-bol) (point-at-eol)))
        (when (and (org-at-table-p)
 		  (org-table-cookie-line-p line))
-	 (setq cnt 0 aligns nil)
+	 (setq cnt 0 cookies nil)
 	 (mapc
 	  (lambda (x)
 	    (setq cnt (1+ cnt))
-	    (if (string-match "\\`<\\([lrc]\\)" x)
-		(push (cons cnt (downcase (match-string 1 x))) aligns)))
+	    (when (string-match "\\`<\\([lrc]\\)?\\([0-9]+\\)?>\\'" x)
+	      (let ((align (and (match-end 1)
+				(downcase (match-string 1 x))))
+		    (width (and (match-end 2)
+				(string-to-number (match-string 2 x)))))
+		(push (cons cnt (list align width)) cookies))))
 	  (org-split-string line "[ \t]*|[ \t]*"))
 	 (add-text-properties (org-table-begin) (org-table-end)
-			      (list 'org-forced-aligns aligns))))
+			      (list 'org-col-cookies cookies))))
       (goto-char (point-at-eol)))))
 
 (defun org-export-remove-special-table-lines ()

lisp/org-html.el

@@ -1980,8 +1980,8 @@ for formatting.  This is required for the DocBook exporter."
 
   (let* ((caption (org-find-text-property-in-string 'org-caption (car lines)))
 	 (label (org-find-text-property-in-string 'org-label (car lines)))
-	 (forced-aligns (org-find-text-property-in-string 'org-forced-aligns
-							  (car lines)))
+	 (col-cookies (org-find-text-property-in-string 'org-col-cookies
+							(car lines)))
 	 (attributes (org-find-text-property-in-string 'org-attributes
 						       (car lines)))
 	 (html-table-tag (org-export-splice-attributes
@@ -1994,9 +1994,9 @@ for formatting.  This is required for the DocBook exporter."
 	 tbopen line fields html gr colgropen rowstart rowend
 	 ali align aligns n)
     (setq caption (and caption (org-html-do-expand caption)))
-    (when (and forced-aligns org-table-clean-did-remove-column)
-    (setq forced-aligns
-	  (mapcar (lambda (x) (cons (1- (car x)) (cdr x))) forced-aligns)))
+    (when (and col-cookies org-table-clean-did-remove-column)
+      (setq col-cookies
+	    (mapcar (lambda (x) (cons (1- (car x)) (cdr x))) col-cookies)))
     (if splice (setq head nil))
     (unless splice (push (if head "<thead>" "<tbody>") html))
     (setq tbopen t)
@@ -2057,8 +2057,8 @@ for formatting.  This is required for the DocBook exporter."
 	     (lambda (x)
 	       (setq gr (pop org-table-colgroup-info)
 		     i (1+ i)
-		     align (if (assoc i forced-aligns)
-			       (cdr (assoc (cdr (assoc i forced-aligns))
+		     align (if (nth 1 (assoc i col-cookies))
+			       (cdr (assoc (nth 1 (assoc i col-cookies))
 					   '(("l" . "left") ("r" . "right")
 					     ("c" . "center"))))
 			     (if (> (/ (float x) nline)